Machine for cutting internal threads, &amp;c.



D. E. ROSS.

' MACHINE FOB CU'TTJNG INTERNAL THREADS, 6w.

' ARPLICATION FILED JULY 8. 1915.

1,296,854. Patented Mar. 11, 1919.

5 SHEETS-SHEET l.

- g wuw wif'ncoom D. E. ROSS.

MACHINE FOR CUTTING INTERNAL THREADS, 81c. APPLICATION HLED JULY 8. I915.

1,296,854. 1 Patented Mar. 11,1919.

5 SHEETSSHEET 2.

Patented Mar.11,1919.

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I. o. E. ROSS. MACHINE FOR CUTTING INTERNAL THREADS, 8m.

APPLICATION FILED JULYBv 1915. I

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g i a Patented Mar. 11,1919.

5 SHEETS-SHEET 4.

D. E. ROSS. MACHINE FOR cunme INTERNAL THREADS, aw. APPLICATION FILED JULY 8. I9l5.

1,296,854, Patented Mar. 11,1919.

5 SHEETSSHEET 5- Witnemm DAVID E. ROSS, OF LA FAYETTE, INDIANA, ASSIGNOR TO THE ROSS GEAR AND TOOL COMPANY, OF LA FAYETTE, INDIANA, A CORPORATION OF INDIANA.

MACHINE FOR CUTTING INTERNAL THREADS, 8w.

To all whom it may-concern:

Be it known that I, DAVID E. Ross, a citizen of the United States, residing at La Fayette, in the county of Tippecanoe and State of Indiana, have invented certain new and useful Improvements in'Machines for Cutting Internal Threads, &c. and I hereby declare that the following is a full, clear, and exact description thereof, reference being bad to the accompanying drawings, which form part of this specification.

This invention is a novel machine for cutting channels such. as keyways or threads of any desired pitch in bores or the interior of hollow bodies; and is designed for use in cutting internal threads in sockets or bores which do not extend clear through the objcct or body, and therefore do not permit of the use of the ordinary devices which must extend clear through the object being operated upon. The invention is particularly designed for use in cutting an internal worm channel or screw threads within the shanks of steering gear heads, which heads have hollow sockets that must be internally threaded to engage the external threads on the steering gear shaft.

- The object of the present invention is to produce a machine by which internal threads, or the like, can be cut in such heads, or in other objects which could not be operated on advantageously with the ordinary drilling or milling tools. The invention provides novel means for holding the work to be treated;

novel means for operating the cutting tools;

novel means for lubricating all the parts during the cutting operation; and novel combinations of parts and novel details of construction thereof all of which will be hereinafter explained and epitomized in the claims.

I will describe the invention as embodied in a machine for cutting internal threads in steering gear heads illustrated in the accompanying drawings, in which Figure 1 is a plan view of the complete machine.

Fig. 2 is a side elevation thereof, partly in section, and the driving pulleys being removed.

Fig. 3 is a detail end elevation.

Fig. 4 is an enlarged longitudinal sectional view ofv the work holder and its controlling devices.

Specification of Letters Patent.

Patented Mar. 11, 1919.

Application filed July 8, 1915. Serial No. 38,702.

Fig. 5 is a detail end View of the work holder. 1

Fig. 6 is a detail view of the changeable work support.

Fig. 7 is a detail section on line 7-7 Fig. 4. V

Fig. 8 is an enlarged longitudinal section through the cutter head.

Fig. 9 is a transverse section on line 9-9- Fig. 8.

Fig. 10 is a detail section on line 10-10 Fig. 9.

Fig. 11 is a detail section on line 1111 Fig. 8.

Figs. 12 and 13 are detail views of the means for throwing the worm gear for driving the work holder into and out of operative engagement.

Figs. 14 and 15 are detail diagrammatic views illustrating a work holder and sleeve adapted to cut an irregular groove or slot. Figs. 16 and 17 are detail sectional views of cutter heads showing modifications of the cutting tool driving means therein.

The particular machine shown in Figs. 1 to 11 of the drawings comprises a preferably cylindric housing 1 which may be suitably mounted upon a bracket 1 attached to a bed plate 10; and secured within this housing is a sleeve 1 (Fig. 4) which as shown is internally threaded to correspond with the pitch of the threads which it is desired to cut in the object being operated upon. The sleeve 1 is preferably provided with keys 1 on one end engaging slots in the adjacent end of the housing (see Fig. 4) to prevent the sleeve rotatlng.

Within this sleeve 1 is; an exteriorly .threaded rotatable cylinder or work-holder 2 that is adapted to carry the objectto be operated upon. Mounted on this work holder is an annular gear 2*, preferably a worm gear, which may be provided with a key 2 engaging a longitudinal key slot 2 (Fig. 7)

gitudinal movement relative to the housing by any suitable means, an annulus or end advance the work-holder at the proper speed" and in accordance with the cutting.

The sleeve 1 and the work-holder. 2 how- 1 0 ever are preferably made removable from the housing, and I propose to employ interchangeable sets of sleeves and work-holders having engaging threads of various pitches; so that when it is desired to cut a certain pitched thread in an object, a work-holder and sleeve having a correspondin ly pitched threaded engagement with each ot er, can be placed withm the housing and operated as ereinafter explained. If it is desired to cut an-irregular groove or channel in the work the work-holder will be so controlled that the cutting tool will cut a groove of the desired lead or contour in the work. For simplicity of explanationI will first explain it as adapted to cut a worm or spiral groove.

The work may be secured in the holder by any suitable means. As shown the .workholder 2 has a removable supporting member 2 fitted in one end thereof and adapted to support the end of the object to be operated upon. In the drawings the work H is shown as a steering gear head, which has a socket It in one end that must be internally threaded and an axial bore h in its other end. The support 2 may be removable, and mterehangeablesupports may be provided to suit heads or objects of diiferent size or contour. The support 2 can be secured in the holder by means of an annular nut 2 screwed into the adjacent end of the holder 2 as shown, and confining the. support 2 therein. 7

The other end of the object H may be supported in the holder by means of a screw 3 which is tapped through a head block 3 that is removably'secured in the rear end of the holder, the reduced inner end 3 of the screw beingentered in thebore h of the head H (Fig. 4). As shown this head block 3 is provided with radially projecting lugs 3 adapted to engage similarly disposed key slots 2 in the rear end of the holder 2 (Figs. 4 and 5). Said head block 3" can be nserted in the end of the holder by en tering its lug in the mouths or the slots and then by giving thehead block a quarter turn the lugs 3 engage and lock in slots 2 (Fig.

. 5) securely locking the head block in the holder; then screw 3 can be turned, as by means of a hand wheel 3 on its outer end, so as to clamp the object H' securely between the block 3" and the nut 2 In the example shown the forward end of the object H is supported in the member 2? and its rear end, which has a cylindrical Mounted adjacent to and in axial alinement with the work-holder is a novel cutter head, or cutting tool carrier, which is adapted to enter the work-holder and the object therein and cut within the latter a groove or channel straight or curved, regularly or irregularly, according to the motion impart ed to the work-holder; and if this motion be a spiral forward movement, (such as would be caused by rotation of the holder 2 within the threaded sleeve 1 indicated in the drawings), the tool would cut a spiral channel within'the head H, or object secured in the holder, exactly corresponding to the lead of the engaging screw threads of the work-holder and sleeve. The cutting tool of such head is adapted to operate at right angles to the axis of the head and to rotate at high speed, and in my invention the desired rotation of the milling tool or cutter is efiected while the cutter head itself can remain stationary.

In the construction shown in Figs. 8 to 11 the cutter head is preferably composed of two longitudinally channeled members 4, 4 (Fig. 8) which are semi-cylindric in external cross section and are fitted together longitudinally as indicated in'Fig. 11 so as to have a preferably cylindric exterior in cross ternally threaded ends of the said members,

the caps being of substantially the same external diameter as the head, see Fig. 8.

The members 4, 4 are provided near one end with diametrically opposite openings in which are placed bushings 5 for the rotary cutters 5 which as shown may project on both sides of the cutter head, but one may be dispensed with if desired; said cutters are attached to a central pinion 5 which lies within a longitudinal channel 4 formed between the members 4, 4 (Fig. 11). Pinion 5 meshes with the last one of a train of pinions 5 also lying Within the said longitudinal channel; each pinion 5 having hub portions journaled in bushings 5 which are fitted within diametrically opposed sockets in the members 4, 4*, said pinions being also preferably provided with axial openings through which pass screw bolts 5 the heads of which fit -in countersunk openings in the member 4 and the threaded portions of which engage threaded apertures in the member 4*. Thus as shown in Fig. 8 it will be seen that each pinion 5 has its hub jour naled in bushings in both members 4, 4 and is prevented from lateral axial displacement by said bushings, and spreading of the members 4, 4 is prevented in the axial line of each pinion by means of the screw bolts 5.

The first gear 5, farthest removed from the pinion 5 meshes with a pinion 5 in the channel but fast to a stub shaft 5 which is journaled in bushings 5 in diametrically Opposed openings in the members a, 4; said shaft 5 extends outside the cutter head. A. suitable gasket or packing ring 5 may be provided to prevent leakage of the lubricant from the cutter head around shaft 5 Small oil passages 4 may be provided in the member 4 communicating with the bearings of the several gears 55 so that oil or lubricant can readily flow through the bearings.

Referring to Fig. 8 when shaft 5 is rotated the cutters 5 will be also rotated therefrom by reason of the intermediate gears, but all such gears are contained within and protected by the cutter head as described; and the only visible movable parts are the projecting end of the shaft 5*, and the projecting ends of the cutters 5.

As indicated in Fig. 17 the cutter 5 may be provided with a gear 12 meshing with a gear 12 on a shaft 12 extending longitudinally through the cutter head, and said shaft 12 is driven by a gear 12 meshing with a gear 12 on shaft 5 The said gearing may be toothed or worm gearing as preferred.

as shown in Fig. 16 the cutter 5 may be provided with a sprocket pinion 13 driven by a sprocket chain 13 from a sprocket pinion 13 on the shaft 5 within the cutter head.

I however prefer to use the arrangement of pinions shown in Fig. 8, but do not consider my invention in its broader sense limited to the particular means shown for imparting rotary motion from driving shaft 5 to the cutting tool 5 by mechanism within the cutter head.

The outer end of the cutter head may be rigidly mounted and secured in any suitable manner within a support 4t" attached to the bed plate 10; and oil is supplied to the outer end of the cutter head 4 by a pipe 4: connected with a suitable supply. Preferably this oil should be supplied by a pump in suf ficient quantity to practically keep the gearing in the cutterhead flooded with oil, and

' vsu'liicient to cause the oil to escape past the cutters into and through the work-holder and carry off thecuttin s.

The cutter head ispre erably held stationary and the object presented to the cutter head, and turned relatively thereto if desired, by the linear movementof the workliolder toward the cutter head and the axial rotation of said work-holder.

The cutters 5 may be rotated at an desired speed by power applied to the sha 5*; which may be rotated in any suitable manner. In the machine shOWn shaft5 is suitably coupled to a shaft 6 mounted in suitable bearings upon bed plate 10 and carrying fast and loose pulleys 6 6 which may be driven by means of a belt from an suitable prime mover; and this same shaft may operate the pump, not shown, by which the oil or lubricant is supplied through the pipe 4: to the cutter head.

As shown in Figs. 1-3 gear 2 meshes with a worm 7 on a counter-shaft 7 a carrying a pinion 7 driven by a series of reducing gears 7, 7 fromagear 7", which is rotated by means of a worm 7 on'a countershaft 7 which in turn is operated by means of a worm gear 7 from a worm 6 on shaft 6. The said gears are mounted in suitable supports on bed plate 10 and the gearing is so proportioned that the cutting tools 5' will be operated at high speed relativeto the movement of the work-holder, the relative speeds being such that the cutters 5 will be given ample time to thoroughly perform their work in cutting the grooves in the object 'without injury to the mechanism.

The shaft 7 carrying the worm 7 and pinion 7 is preferably journaled in a cast- .ing 11 which is. provided with lugs 11 by 11 may be moved 1n or out by hand, and, when pushed inward will raise the worm 7 into engagement with the gear 2 or permit worm 7 to disengage gear 2 by gravity when the cam plate is drawn outward, as indicated in dotted lines Fig. 13.

The mode of operating the machine in cutting internal screw threads within a steering gear head of the type indicated in the drawings is as follows A work-holder 2 and sleeve 1 (having a threaded engagement corresponding to the desired pitch of the thread or channel to be cut in the object)are placed in the housing 1, a suitable work support 2 having been secured in the inner end of the work-holder. The work-holder is then backed out of the sleeve 1 sufficiently to clearthe cutter head. The block 3 is then given a quarter turn so as to disengage its lugs from the slots in the. work-holders 2, then the object, or head, H to be treated is inserted within the Workholder, the inner end of said object being engaged with the support 2. The block 3 is then replaced and the end '3 of the screw 3 enga ed in the bore in the adjacent end of the object. The block 3 is then locked in 'vanced by reason of its threaded engagement with the sleeve 1*, thus causing the relatively stationary cutters to produce the desired lead of thread or spiral groove in the object, such lead corresponding with the lead of the screw threads engaging the workholder with the sleeve.

The cutting or lubricating oil flows through the cutter head past all the small gears and leaks out through the small openings. at the'sides of the gears, but most of the oil flows on through to the cutting tools 5. Preferably the oil is caused to flow through the cutter head in sulficient volume .to keep the cutters cool and wash out the cuttings. I

When the work has been finished worm 7 should be tripped by drawin out the cam plate 11, and then the wor -holder 2 is rotated backwardly by turning the hand Wheel 3; the gear 2 then-rotating freely with the holder 2 and slidingalong the latter by reason of its engagement withkey 2 in slot 2. When the work-holder 2 is in its rearmost position and entirely clear of the cutting tools, the worm 7 may be again engaged with wheel 2 by moving the cam plate 11 inward, and then further rotation of the wheel 3 causes screw 3 to partly release the work, and as soon as this is accomplished the block 3 can be partly turned so as to disengage lugs 3 from slots 2 and the block can be readily withdrawn from the work-holder; then. the finished piece of work may be removed and another object inserted and clamped in the workholder as above explained. I

In the drawings I have shown the cutter head as provided with two cutters 5, which are used where it is desired to simultaneously out two similar but independent grooves'in' the object; and in steering gear heads, such as indicated at H in Fig. 4, it is customary to cut double threads; and this is readily accomplished'because the two cutting tools are diametrically opposite. A

As above stated the external threads on the work-holder should correspond exactly in pitch with the lead desired for the grooves to e cut within the object being operated upon, but I do not consider the invention restricted to the use of such threads. Where the work-holder has'a regular pitch threaded engagement with the sleeve 1 the work will be correspondingly regularly threaded or grooved, but as stated the machine can a tooth or key lug B fixed in the sleeve 1 and engaging said groove 6 and thus causing the cutting tool to cut an irregular groove in the object, as indicated in Fig. 15. This merely illustrates but one of various forms of irregular grooves which might 8 be cut, and the proper manner of designing the controlling groove for any desired groove or channel will be obvious to persons familiar with the invention. With this invention it will be seen the cutter need make 8 but one trip through the work, as it can do all the work of cutting during one complete operation of the work-holder. It would'be possible to employthe novel cutter head without necessarily employing the particu 9 lar form of work-holder shown. The cutting tool can be introduced within a socket or closed end openingand rotary motion imparted to such tool from a point outside the socket, and at the same time the path or'lead 9 of the cutter through the object being cut is controlled. The invention can be readily adapted to cut any desired helix of any pitch, or out anything from a straight line to a true circle depending upon some prede- 1 termined master controller.

In the machine shown the cutter head is shown as relatively fixed and the work is advanced to the cutter head, and this is the preferred form, though it would he 'possi- 1 ble to have the relative motion of the parts reversed, so that the cutter head would move to and from the work which might be held relatively stationary to the cutter either axially or rotatorily, or both. 1

What I claim is:

1. In a machine for the purpose specified the combination with a work holder adapted to hold an object to be internally threaded, a cutter head having a cutting tool project- 1 ing laterally near one end thereof adapted to project into said holder, a drive shaft entering said head at a point outside the holder, and means within the head for operating said cutting tool from said shaft; with means for producing both relative rotatorial movement and also relative linear movement of the work. holder and cutter ject into said work holder and the object therein, said cutter head being provided with internal means for rotating said cutter, and having external means at a point remote from the cutter whereby the internal means may be driven so as to rotate the cutter at high speed; with means for producing both rotatorial and simultaneously linearrelative movements of the Work holder and cutter head.

3. In a machine for the purpose specified, a work holder, a support therefor, a cutter head supported at one end and having its other end adapted to project into the work holder to engage the object therein, a'

I radially disposed cutting tool projecting from and adjacent the inner end of said cutter head, a driving shaft projecting radially from said cutter head at a point re mote from the cutting tool, and means within the cutter ,head for driving the cutting tool from thesaid shaft; with means for producing'both longitudinal and rotatorlal movement of the work holder relative to said support. I

i. In a machine for the purpose specified, a cutter head provided with a radially disposed cutting tool adjacent one end and means within the cutter head for transmit- ,ting motion to said cutter from a point re- 5. In a machine for the purpose specified, a tubular work holder, means for securmg an object to be operated upon within said work holder, a Work holder support and means for producing both longitudinal and rotatorial movement of the work holder relative to said support; with a cutter head comprising an elongated sectional body supported at one end and having its other-end adapted to enter the work holder to engage the object therein, a radially disposed cutter projecting from and adjacent the inner end of said cutter head, a driving shaft projecting radially from said cutter head at a point remote from the cutting tool, and means within the cutter head for driving the cutting tool at high speed.

6. In a machine for the purpose specified the combination of a housing, a work holder therein having a threaded engagement therewith, and means for rotating said work holder; with a cutter adapted to enter the work holder to cutthe object therein, the lead of the thread on the work holder corresponding with the lead of the groove cut by the cutter head in the object being operated upon but independently of the cutter.

7. In a machine for the purpose specified the combination of a housing, a work holder a threaded engagement therewith whereby it is caused to move lineally as it is being turned, a gearsplined on said work holder, and means for rotating said. gear; with a cut ter head adapted to enter the work holder and cut the object therein, the lead of the thread -on the work holder corresponding with the lead of the groove cut by the cutter head in the object being operated upon but independently of the cutter.

9. In combination, a housing, a work holder therein and means whereby it is caused to move lineally as it is being turned; with a cutter headdisposed in line with the work holder and having one end adapted to project into and engage a socket in the object carried by the holder, a radially disposed cutting tool adjacent the inner end of said cutter head, and means in the head for transmitting motion to the cutter.

10. In combination, a housing, a work holder therein having external threads whereby it is caused to move lineally as it is being turned, and means for supporting within the work holder an object to be threaded; with a cutter head disposed in line with the work holder and having one end adapted to project into the work holder and engage a socket in the object therein, a

therein having external threads whereby it is caused to move lineally as it is being turned, means for rotating said work holder, and means for supporting within the work holder an object to be threaded; with a cutter head disposed in line with the work holder and having one end adapted to proj ect into the work holder and engage a socket in the object therein, a cutting tool adjacent the inner end of said cutting head, and means within the head for transmitting motion to the cutter.

12. In combination, a housing, a' work holder therein having external threads whereby it is caused to move lineally as it is being turned, means for supporting within the work holder an object to be threaded; with a cutter head dis osed in line with the work holder and havmg one end adapted to enter the work holder and engage a socket in the object therein, a radially disposed cutting tool at the inner end of said cutter head, a radially disposed driving shaft mounted in said head remote from the tool, and means in the head for transmitting motion from the driving shaft to the cutter; the lead of the external threads on the work holder corresponding with the lead of the groove out by the tool in the object being operated upon but independent of the cutter.

13. In a machine of the character specified, a work holder comprising a hollow body, a work support at one endthereof, a removable screw detachably engaged with the other end of the body and having'its inner end adapted to engage one end of the 7 port.

15. In a machine, of the character specified, a work holder comprising a hollow body, a removable work-support at one end thereof, a removable block detachably engaged with the other end thereof, and a screw tapped through. said block and having its inner end adapted to engage one end of the work or object while the other-end of said object is engaged in said'support.

16. In, a machine for the purpose specified the combination of a housing, a sleeve therein, a work holder in said sleeve having a threaded engagement therewith whereby it is caused to move lineally as it is being turned, a gear splined on said work holder, means for rotatingsaid gear, and means for throwing said gear into or out of opera- ,tion; with a cutter. adapted to enter said work holder and operate upon the object held therein, substantially as described.

17. In a machine for the purpose specified the: combination of a. housing, a work holder therein, a radially projecting outwithin the work holder,

turned, means for turning said work holder, and means for securing an object to be operated upon within the work holder.

18. In a machine for the purpose speci-.

'fied, a housing, a tubular work holder in said housing having a threaded engagement therewith whereby the holder will be caused to move lineally when rotated, a radially projecting cutter operating within the work holder, and means. for rotating said holder. 19. In a machine for the purpose specified the combination of a housing, a work holder therein, means whereby the holder is caused 'to move lineally as it is being turned, a

worm gear splined on said work holder, and means for rotating said gear, with a radially disposed cutter head adapted to enter the work holder, and means for rotating the cutter head.

20. In a machine for the purpose specified the-combination of a housing, a work holder therein having external threads whereby it is causedto move lineally as it is being turned, means for rotating said work holder, and means for securing an object to be threaded within the work holder, with a support adapted to be entered into the work in the work holder, a radially disposed cutter on said support, and means for rotating the cutter. a v

21. In a machinefor the purpose specified, a housing, a removable sleeve in said housing, a tubular work holder in said sleeve, means whereby the holder will be caused to move lineally when rotated, and means for rotating said holder, with a cutter support adapted to be entered into the work in the work holder, a radially disposed cutter on said support, and means for rotating the cutter.

22'. In a machine for the purpose specified, a housing, a removable sleeve in said housing, a tubular work holder in said sleeve and having a threaded engagement therewith whereby the holder will be caused to move lineally when rotated, and means for rotating said holder, with a radially disposed cutter head adapted to enter the work holder, and means for rotating the it is caused to move lineally as it-is being turned, a gear splined on said work holder, and means for rotating said gear,with a cutter support adapted to be entered into the work in'the work holder, a radially disposed cutter on said support, and means for rotating the cutter.

24. In a machine for the purpose specified the combination of a housing, a work holder therein, means whereby the work holder is caused to move lineally as it is being turnai, and means for rotating said holder; with a cutter supportadapted to. enter the work holder, a radially disposed cutter on saidsupport adapted to cut the object therein, the lead ofithe groove cut 'by the cutter being determined by the movement of the work holder independently of the cutter.

25. A cutter head comprising a pairof opposite complemental bars having longitudinal internal grooves; a cutting tool shaft arranged diametrically of the head ide and journaled in suitable hearings in the opposite bars; a driving shaft arranged diametrically of the head and .journaledin suitable bearings in the opposite bars; and a train of gears within the head having projecting hubs journaled in recesses in the bars and adapted to transmit motion from the driving shaft to the cutter.

26. A cutter head comprising a body formed of opposite bars having longitudinal internal grooves; a cutting tool shaft journ'aled in said bars; a driving shaft ournaled in. the bars remote from the cutting tool shaft; a pinion in the body connected with the tool shaft; a pinion in the body connected with said driving shaft; a series of intermediate pinions in the body transmitting motion from the pinion on the driving.

shaft to the pinion on the cutter, said pinions having projectin hubs 'journaled in the bars, and stud b0 ts extending axially ,through the'said intermediate pinlons and uniting the opposite bars to prevent spreading of the body.

27. A cutter head comprising a pair of longitudinal oppositely grooved bars; a cutting toolshaft arranged diametrically of the head and journaled in suitable bearings in the opposite bars; a driving shaft arranged diametrically of the head and journaled in suitable bearings in said bars; a series of intermediate gears in the head for transmitting motion from the driving shaft to the cutter shaft, each of said intermediate gears being provided with projecting hub portions at each side journ'aled in openings in the opposite bars, and stud bolts extending axially through the hubs of said intermediate gears-and uniting said bars to prevent spreading of the cutter head.

In testimony that I claim the foregoing as my' own, I aflix my signature in presence of two witnesses.

DAVID E. ROSS.

Witnesses:

GEO. C. KUMMING, D. L. Ross. 

